Filling machine



United States Patent [72] Inventor Robert J. Gruodis Oak Lawn, Illinois [21] Appl. No. 688,200 [22] Filed Dec. 5, 1967 [45] Patented Oct. 20, 1970 [73] Assignee Continental Can Company Inc.

New York, New York a corporation of New York [54] FILLING MACHINE 7 Claims, 5 Drawing Figs.

[52] US. Cl 141/1, 141/150, 141/172 [51] Int. Cl 8135b 43/42 [50] Field ot'Search 141/1, 148150,171 172, 275, 277, 278; 198/103, (Consulted cl. 74)

[56] References Cited UNITED STATES PATENTS 3,050,090 8/1962 Luther 141/150 3,386,480 6/1968 Riesenberg 141/150(X) 3,421,555 1/1969 Minard etal. 141/150 OTHER REFERENCES Rothbart, H. A Cams, Design, Dynamics, and Accuracy, N.Y,, J. Wiley & Sons, Inc., 1956, pp. 3940. TJ 206R6 Primary Examiner.Laverne D. Geiger Assistant Exqminer-Edward J. Earls Att0rneyGreiSt, Lockwood, Greenawalt and Dewey ABSTRACT: A rotary machine for filling containers with liquid products having vertically aligned filling heads and spring urged cam controlled container supporting platforms spaced about the periphery of a supporting turret which is adapted to be operated at a relatively high speed and which is characterized by a special cam arrangement for lowering the platforms when filling is completed so as to disengage successive containers from the filling heads and permit removal thereof onto a takeoff conveyor, the cam being a nonsymmetrieal double harmonic type which results in a minimum tilt angle on the top surface of the liquid in each container for a given turret speed and enables the turret to be operated at a substantially higher speed without increasing the tendency of the liquid to spill over the outer edge of the containers due to the centrifugal forces generated by rotation of the supporting turret.

Patented Oct. 20, 1970 Sheet 1 of 2 INVENTOR R BERT J. GRUOD/S BY 3 ATT'YS.

Patented Oct. 20, 1970 Sheet TIME dii TRAVEL RATE OF ACCELERATION INVENTOR ROBERT J. GRUOD/S ui/w? ATT'YS.

- FILLING MACHINE This invention has to do with packaging and is more particularly concerned with improvements in a machine for filling containers with a flowable product.

Machinery has been developed for filling containers such as metal cans with a liquid product, for example, beer, soft drinks and the like, in which a plurality of filling heads are carried in a horizontal plane on a rotating turret and the open top containers are supported on vertically reciprocating platforms which are spring urged upwardly with cam control so as to lift the top of the container into the filling head and hold it there during filling and after the filling is completed the platforms are lowered and the filled containers are transferred to a takeoff conveyor which leads to capping equipment for application of a closure or to other processing equipment. In the operation of this type filling machine a relatively large turret is generally employed with a large number of filling heads so as to provide adequate time for the filling cycle with the turret rotating at a relatively high speed in order to obtain as high a production rate as possible. One of the limitations on the speed with which this type filling machine can be operated results from the centrifugal force to which the liquid product in the container is subjected due to the high speed rotation of the turret. The top surface of the liquid is caused to slope outwardly and upwardly away from the center of the turret by the centrifugal acceleration induced by the rotation of the turret. A relatively small headspace is generally provided for in filling the containers and the turret is operated at a speed which will not result in the liquid spilling over the outermost edge of the container due to centripetal force. After the filling is completed the successive containers are lowered by a cam track onto which the cam follower on the supporting platform advances so that the top of the container will clear the filling head when it is moved out of the circular path of the turret and transferred to the takeoff conveyor. The depressing of each successive platform to enable the successive containers to be transferred to the takeoff conveyor must be accomplished in a relatively short period of time with the period being shorter the more rapidly the turret is rotating. With the cam track arrangement which has heretofore been employed in this'type of machine too rapid acceleration of the container as it is dropped away from the filling head at the start of the descending movement of the supporting platform has added a further limitation to the speed with which the turret can be operated since a high rate of acceleration as the container moves down out of the filling head causes the container to move down faster than the liquid contents and consequently increases the tilt angle of the top surface of the liquid and causes it to spill over the outer edge of the container at a lesser turret speed. The resultant downward acceleration factor induced by the pull down cam combines with the centrifugal acceleration factor and increases the tilt angle of the liquid in the container. Also, as the container separates from the filling head liquid adheres to the filling tubes and is pulled out of the container. These factors have held down the speed with which the rotary filler can be operated without excessive spillage. An object of the present invention, therefore, is to provide an improved system and apparatus for handling the containers on a rotary filling machine after the filling is completed so as to avoid spillage during transfer of the filled containers to the outfeed conveyor while at the same time enabling the turret to be operated at a higher rate of speed than heretofore considered possible.

It is a more specific object of the invention to provide in a rotary container filling machine an improved arrangement for lowering the containers after the filling cycle has been completed so as to clear the filling heads when the filled containers are transferred from the filling turret toan outfeed conveyor which enables the containers to be lowered with a minimum of acceleration at the beginning of the descending movement followed by a rapid deceleration which reaches a maximum at the transfer point so as to provide a minimum tilting force on the top of the liquid.

It is another object of the invention to provide in a rotary machine for filling containers with a liquid wherein the filled containers are transferred from the filling turret at the end of the filling cycle to a generally tangential takeoff conveyor with the lowering of the containers on the turret so as to clear the filling heads during transfer being controlled by a special cam having a double harmonic profile which operates to pull down the successive container supporting platforms, the cam providing for minimum acceleration during the initial downward movement of the supporting platform whereby to lessen the tendency of the liquid to spill over the top edge of the container due to the forces acting on the liquid at the top of the container.

These and other objects and advantages of the invention will be apparent from a consideration of the apparatus which is shown by way of illustration in the accompanying drawings wherein: FIG. 1 is a partial plan view, partly schematic and with portions broken away or omitted, which shows a rotary container filling machine having the principal features of the invention embodied therein;

FIG. 2 is a partial side elevation of the machine of FIG. 1, the view being taken on the line 2-2 of FIG. 1 and showing the area where the containers are transferred from the filling turret to a straight line takeoff conveyor;

FIG. 3 is a fragmentary cross section taken on the line 3-3 of FIG. I; I

FIG. 4 is an elevational view showing the profile of the stirrup pulldown cam; and

FIG. 5 is a graph showing the acceleration curve of the pulldown cam.

Referring to the drawings, there is illustrated a rotary machine for filling open top containers which comprises a turret wheel having a plurality'of filling heads 12 spaced circumferentially about the periphery thereof and above supporting platforms 14 on which the containers to be filled are carried in a circular path. The platforms for supporting the containers C, which may be, for example, beer or soft drink cans, are carried on the wheel 10 in vertical alignment with the filling heads 12. The empty containers C are delivered to the platforms 14 by an infeed wheel 15 from a supply chute or other supply source. This general type of filling machine is well known and only such details as are required for an understanding of the invention will be described. The machine illustrated is provided without the present improvement by Leo. J. MeyerManufacturing Company of Milwaukee, Wisconsin.

Each of the filling heads 12 depends from a top ring 16 of the turret wheel 10 and has a downwardly opening recess 18 in the bottom face thereof with a sealing gasket 20 which is engaged by the top rim of the container C when the latter is elevated by vertical movement of the platform 14 to telescope the top of the container C into the head 12. A series of peripherally-spaced filling tubes 22 in each head 12 extend into the mouth of the container during the filling operation through which liquid from a supply source (not shown) is dispensed into the container. Other details of the head may be as shown in Meyer U.S. Pat. No. 3,050,091 dated Aug. 21, 1962. Each of the platforms 14 includes an upstanding wall section on the turret side of the platform with an outwardly opening recess 24 in which the bottom chine of a container C is adapted to be seated. Each platform 14 is mounted on a pistonlike stem 25 which extends upwardly from a cylinder or chamber 26 in a lower ring 28 of the turret 10. A coil spring 30 or other force applying element is enclosed in the cylinder 26 for constantly urging the platform 14 in an upward direction. A cam follower roller 32 is mounted on a stub shaft 34 extending from the inside wall of the platform 14 which cooperates with a cam track 35 extending about the periphery of the wheel 10 for controlling the vertical position of the platforms ,1. 14. During the filling operation the cam track allows the platform to be held in raised position so as to hold the top of the container in the recess 18, with the rim against the sealing gasket 20, during the filling cycle.

At the end of the filling cycle or a short distance beyond the same the containers enter a takeoff area where they are moved out of the circular path of the turret wheel and onto a conveyor platform 36 which is at predetermined level and which extends along the path of a conveyor chain 38 having longitudinally spaced container engaging fingers 40 with recesses 42 conforming generally to the outside wall contour of the containers C. The chain 38 is carried on end sprockets 44, only one of which is shown, and the path of the chain extends in a straight line outside the periphery of the turret wheel 10 and parallel to a tangential line thereto. A suitable guard rail 45 extends along the inside of the conveyor platform 36 so as to hold the containers in contact with the fingers 40.

A pulldown cam 50 having a special track profile 51 is mounted a short distance beyond where the fill is completed and extends to the takeoff point where the filled containers are removed to the platform 36 of the takeoff conveyor. An outer guard rail 52 is disposed opposite the pulldown cam 50 at an elevation so as to be engaged by a side wall portion of each container C as it passes through the takeoff point. The guard rail 52 has an inside track forming edge 54 which is profiled so that the containers are spiraled outwardly onto the conveyor platform 36 where they are picked up by the conveyor fingers 40 and advanced away from the turret 10.

The pulldown cam 50 has a specially designed track profile for engagement by the cam followers 32 so as to control the movement of each successive container downwardly away from the filling head 12 in a predetermined manner. The cam 52 is a double harmonic cam of nonsymmetrical type which provides maximum downward acceleration of smaller magnitude than a cyclodial cam or any other cam arrangement which has heretofore been employed. The cam 50, which may be designed according to the principles set out in Cams, Design, Dynamics, and Accuracy by Harold A. Rothbart (pages 39 and 40); has an acceleration curve as illustrated in FIG. 5, which is unsymmetrical and which is composed of the difference between two harmonic motions, one being one quarter of the amplitude and twice the frequency of the other. The curve, which is obtained by plotting the rate of acceleration and distance (arcuate length of the cam track) or elapsed time of travel along the cam track as vertical and horizontal coordinates, shows that there is a slow rate of acceleration at the beginning of travel which reaches a maximum, drops off more rapidly through a zero point and then decelerates to a maximum, at the end of the cam track, the transfer of the container from rotary to straight line motion being effected at the point of maximum deceleration. The time allowed for dropping the container to the takeoff level is controlled by the cam 50 and held to a minimum for the rotational speed of the turret. A small rate of acceleration is desirable at the beginning of the downward movement of the containers because it helps to maintain the liquid in the top of the containers at a lesser tilt angle. The rate of acceleration induced by the cam 50 at the start of the downward movement reaches a maximum and diminishes to zero as the container advances to a point midway of the ends of the cam track, rapid deceleration then occurs which extends to a maximum at the end of the cam cycle where the container C is transferred out of its circular path and centrifugal force is reduced to zero so that the top surface of the liquid is no longer affected by centrifugal force and there is a little, if any, tilt in the top surface of the liquid with no tendency to spill over the edge of the mouth of the container. With a nonsymmetrical cam such as the double harmonic provides the magnitude of the deceleration vector is much larger than that of the acceleration vector and the maximum deceleration is attained at the end of the cam cycle. Since liquid in the container attains a minimum tilt angle at maximum container deceleration with the double harmonic cam the liquid level experiences a reduction in the tilt angle as it continues through the entire cycle of a deceleration phase and minimum tilt angle is experienced at the end of the cam cycle when the container is ready to be transferred to the takeoff conveyor chain. Thus, the cam 50 serves to substantially reduce the tendency of the liquid to spill over the outer edge of the container mouth and, with the same head space allowed, enables the turret wheel 10 to be operated at a higher speed, without spillage, than is possible with any other arrangement for handling the containers at the transfer point in n this type filling machine.

The filling machine is, of course,adapted to be operated in the same manner as a machine of conventional construction except that higher rotational speed may be imparted to the turret wheel 10 so as to obtain a substantially higher production rate. The empty containers C are fed onto the supporting platforms 14 by the feed plate or wheel 15 which is driven in properly timed relation to the operation of the filling wheel 10. The containers C are elevated by the operation of the stirrup mechanism 14, with the rise thereof limited-by engagement of the cam followers 32 with the downwardly facing track of cam 35, so as to engage the container rims with the sealing gaskets 20 in the sealing heads 12. The containers are held in elevated position while they are filled to a predetermined level with the liquid product which is dispensed through the tubes or spouts 22. The time required for the filling of each container C is substantial and will generally equal more than one-half a single rotation of the wheel 10. When the filling is completed, or slightly beyond this point, the cam follower 32 on each successive platform 14 engages the cam section 50 and the filled container is lowered to free the top from the head 12 so that it may be removed from the supporting platform 14 and transferred to the straight line conveyor platform 36 for pick up by a container engaging finger 40 on the traveling chain 38. The lowering of the successive platforms 14 is controlled by the track on the cam section 50 in the manner heretofore described so as to minimize the forces acting on the liquid product which tend to cause spillage over the outermost top edge and to enable the turret wheel 10 to be rotated at a speed higher than heretofore possible for the particular liquid product and the head space desired, without causing spillage during the transfer of the filled containers to the takeaway conveyor. The chain 38 or other takeaway mechanism is of course, driven at the proper speed to accept the filled containers from turret wheel 10 and advance them out of the way of succeeding containers.

Iclaim:

1. In a machine for filling open top containers with a liquid product to a predetermined level adjacent the top edge of the containers, said machine having a rotating turret and means thereon for supporting individual containers disposed at a plurality of spaced, circumferential points, said turret having peripherally spaced filling heads and associated means for dispensing the product into the containers, the filling heads being vertically aligned with the individual container supporting means and each having a downwardly opening recess in which the top of the container is seated during filling, said container supporting means each being vertically movable and having means for urging the same upwardly to bring the containers into engagement with said filling heads, each said container supporting means having a cam follower, cam tracks disposed about the path of movement of the containers for engagement by the cam followers so as to control the vertical position of the container supporting means, a takeofi' conveyor having means to receive the containers from the supporting means at a transfer point and advance the containers away from the turret, said transfer point being located beyond the point where the filling of the containers is completed, and said cam tracks including a section extending between said point where the filling is completed and said transfer point which is engaged by successive cam followers, which cam track section has curved track surfaces constructed to lower each successive container supporting means so as to disengage the containers and filling heads with minimum acceleration at the start of downward movement and progressing through maximum acceleration to zero acceleration and thereafter decelerating and reaching maximum deceleration at the transfer point. I

2. In a machine for filling open top containers as set forth in claim 1, and the section of said cam track extending between the point where the filling is completed and the transfer point having track surfaces characterized by a double harmonic profile so as to lower the containers with a minimum tendency of the liquid surface to tilt as a result of the centrifugal force generated by the rotation of the turret.

3. In a machine for filling open top containers as set forth in claim 1, and the cam track section which extends along the arc traveled by the container supporting means between the point where the filling is completed and the transfer point being provided by a fixed arcuate cam block having a track surface for engagement by the cam followers which is characterized by a double harmonic profile constructed to impart downward motion to each successive container supporting means as it travels between said points, whereby the developed vertical profile of the container carried on each said supporting means as it travels between said points under the control of said cam block corresponds to a double harmonic curve.

4. In a machine for filling open top containers with a liquid product to a predetermined level immediately below the top edge of the containers, said machine having a turret mounted for rotation about a generally vertical axis, vertically movable platforms on said turret for supporting the containers, which platforms are disposed at a plurality of spaced, circumferential points, said turret having peripherally spaced filling heads and associated means for dispensing the product into the containers, the filling heads being vertically aligned with the container supporting platforms and each having a downwardly opening recess into which the top of the container is telescoped during filling, said container supporting platforms having means for urging the same upwardly to bring the containers into engagement with said heads, said container supporting platforms each having a cam follower and cam means disposed about the path of movement of the containers having tracks for engagement by the cam followers so as to control the vertical position of the container supporting platforms, a takeoff conveyor having means to receive the containers at a transfer point and advance the containers in a nonrotative path, said transfer point being located beyond the point where the filling of the containers is completed, and said cam means including a cam section extending between said point where the filling is completed and said transfer point which has a curved track formation with a profile which forces each successive container supporting platform downwardly with predetermined accelerating and decelerating movement, the track profile being a series of connected curves whereby there is a relatively slow accelerating movement of said platform downwardly as the associated cam follower initially advances onto said section with acceleration increasing to a maximum and quickly dropping off to zero as the platform advances to a point intermediate the ends of the section and a rapid decelerating movement beyond said intermediate point which reaches a maximum at approximately said transfer point.

5. In a machine for filling open top containers as set forth in claim 4, and said track section which extends along the arc traveled by the container supporting platforms between the point where the filling is completed and the transfer point and which forces each successive platform downwardly as it travels between said points comprising a fixed arcuate cam block having a track profile throughout its arcuate length which corresponds to a double harmonic curve.

6. in a container filling machine which filling machine is characterized by a turret mounted for rotation in a generally horizontal plane and having a plurality of peripherally spaced filling heads with a container supporting platform mounted for vertical reciprocation beneath each of said filling heads and with each platform having a cam follower adapted to ride on the cam track of a control cam, a control cam member adapted to be installed at the point where the container supporting platforms are to be lowered for lowering and disengaging successive containers from the associated filling heads so as to permit their discharge from the turret, said control cam member having an elon%ate cam track with a series of curved surfaces which provide a double harmonic profile for engagement by the cam followers, said cam profile being formed so as to lower each container supporting platform with a relatively slow acceleration at the start of downward movement which reaches a predetermined maximum and then drops to zero at a point midway between the ends of the cam track and with the downward movement decelerating to a predetermined maximum at the point of transfer from the turret thereby minimizing the tendency of the container contents to spill over the top edge of the container due to the centrifugal force generated by the rotation of the turret, as the container is disengaged from the filling head.

7. A method of separating from the filling head of a rotary filling machine an open top container which has been filled with liquid to a level near the top edge of the container where the container is carried on a vertically movable support aligned beneath the head and advanced at substantially constant angular velocity along a circular path from a point where filling is completed to a point beyond the same where the container is transferred to a noncircular path, which method comprises imparting a low rate of downward acceleration to the container support beginning approximately at the point where filling is completed, slowly increasing the downward acceleration to a maximum and decreasing the acceleration to zero at a point midway between the point where filling is completed and the transfer point and rapidly decelerating the downward movement to a maximum at the transfer point, so as to minimize the tendency of the liquid level to tilt outwardly and spill over the top edge of the container as the container is separated from the filling head due to the centrifugal force generated by the rotation of the turret. 

